The subject matter of the present disclosure broadly relates to the art of vehicle suspension systems and, more particularly, to a jounce bumper assembly that is capable of dynamically tuned performance and a gas spring assembly including the same.
Wheeled motor vehicles of most types and kinds include a sprung mass, such as a body or chassis, for example, and an unsprung mass, such as two or more axles or other wheel-engaging members, for example, with a suspension system disposed therebetween. Typically, a suspension system will include a plurality of spring devices as well as a plurality of damping devices that together permit the sprung and unsprung masses of the vehicle to move in a somewhat controlled manner relative to one another. Movement of the sprung and unsprung masses toward one another is normally referred to in the art as jounce motion while movement of the sprung and unsprung masses away from one another is commonly referred to in the art as rebound motion.
Generally, the range of motion of a suspension system extends between a fully compressed condition and a fully extended condition. To eliminate contact between opposing portions of the sprung and unsprung masses, contact between opposing portions of components of the suspension system or contact between any combination thereof, jounce bumpers are commonly installed on one or more portions of the vehicle to prevent such opposing portions from directly impacting one another. Thus, during jounce motion of the suspension system, an opposing component will contact the jounce bumper rather than impacting the component on or near which the jounce bumper is mounted.
Jounce bumpers of a variety of types, kinds and configurations have been developed and are commonly used. Though the size and shape of jounce bumpers vary widely, known jounce bumpers can generally be grouped into two categories, namely, compliant jounce bumpers and rigid jounce bumpers. The former are commonly formed from materials capable of relatively high deflections under load, and are often formed from rubber or elastomeric foam compounds. Generally, compliant jounce bumpers act to cushion or soften the impact that would otherwise be associated with a sudden movement toward a full jounce condition. As such, compliant jounce bumpers are well suited for use in relatively light duty applications, such as use in the suspension systems of passenger vehicles and light trucks, for example, where ride comfort is a more significant factor. Also, the high axial deflections that would be associated with heavily loading a compliant jounce bumper would generate high corresponding lateral strains in the jounce bumper. Generally, materials that are well suited for comfortably cushioning impacts under full jounce conditions have been found to be poorly suited to such corresponding high levels of lateral strain, which can undesirably modify the performance characteristics of the compliant jounce bumper or even result in permanent deformation of the same.
Oppositely, rigid jounce bumpers are commonly formed from materials that deflect a relatively small amount under load, such as high strength and/or fiber reinforced plastic materials, for example. Rigid jounce bumpers are not normally considered to be well suited for use in light duty applications (e.g., passenger vehicle applications) because of the minimal deflection and high impact associated with the use of such jounce bumpers. However, rigid jounce bumpers are well suited for heavy duty applications, such as in truck, tractor-trailer and other over-the-road vehicle applications, for example, where it is desirable to provide a sacrificial component that can prevent impacts between more permanent and/or expensive components. Additionally, it is often desirable to lower trucks, trailers or other vehicle bodies onto the jounce bumpers to provide a solid foundation for loading and/or unloading of the vehicle body. While high speed impacts acting on the jounce bumper are not an issue in such applications, substantial loads are still commonly involved. As discussed above, compliant jounce bumpers are normally formed from materials that are incapable of withstanding the loads associated with such heavy duty applications. As such, rigid jounce bumpers are commonly used.
Notwithstanding the successful use of rigid jounce bumpers in heavy duty applications, it is believed desirable to develop a jounce bumper that overcomes the forgoing and other disadvantages, such as, for example, by providing a jounce bumper for use in heavy duty applications that is capable of withstanding repeated impacts under the relatively high load conditions associated therewith, but which will also provide increased cushioning and reduced impact at least when initially contacted during jounce movement.